Haibatullah Akhunzada, member of the conservative old guard, to head group whose last leader died in a US drone strike.

An Afghan Taliban spokesman has confirmed the death of Mullah Akhtar Mansoor, the armed group's leader, in a US drone strike and announced the appointment of Haibatullah Akhunzada as his successor.

Agencies on Wednesday quoted the Taliban spokesman as saying that Sirajuddin Haqqani and Mullah Yaqoob, son of former leader Mullah Omar, have been appointed the group's new deputy leaders.

The announcement followed confirmation on Monday by President Barack Obama that Mansoor was killed in a US drone strike in Pakistan's Balochistan province.

Abdullah Abdullah, Afghanistan's chief executive, said on Twitter on Sunday that Mansoor was dead. Afghanistan's spy agency also said he had been killed.

Mansoor was chosen to head the Afghan Taliban last summer after it was announced that the group's longtime leader Mullah Omar had died two years earlier.

The Taliban is the most powerful anti-government group in Afghanistan, where an estimated 11,000 civilians were killed or wounded and 5,500 government troops and police officers died last year alone.

It seized power in 1996 and ruled Afghanistan until it was toppled by a US-led invasion after the September 11, 2001 attacks on New York and Washington.

Almost 15 years later, about 13,000 troops from a US-NATO coalition remain in the country, including about 9,800 Americans.

'Well-known figure'

The Taliban has repeatedly refused to take part in peace talks sponsored by the Quadrilateral Coordination Group, which comprises representatives from Afghanistan, Pakistan, China and the US.

The group also shows no signs of easing its ongoing spring offensive against the Afghan government.

"The new Taliban leader is known to be 'a Stone Age mullah' who strongly believes in the Taliban," Sami Yousafzai, an Afghan expert who has met both the late Mansoor and Akhunzada several times, said.

"The appointment of Akhunzada could affect the peace process. He was very close to Mullah Omar and is known as a hardline mujahid [fighter] who will bring the Taliban together and will make sure the group gets stronger."

A Taliban source, speaking on condition of anonymity, said the Taliban under Akhunzada has pledged to take revenge against foreign forces and the Afghan government for Mansoor's killing.

"They [the foreign forces and Afghan government] should now fasten their seat belts as the attacks will continue and will be stronger than before," he said.

"We will be taking our revenge and will also make sure we come out stronger than before."

The warning coincided with an attack that claimed the lives of at least 10 people on Wednesday.

A suicide bomber on foot detonated his explosives, striking a vehicle carrying court employees near the capital Kabul, according to the the interior ministry.

The Taliban claimed responsibility for the attack.

Taliban leaders dispute

A spokesman for the breakaway faction, Mullah Abdul Manan Niazi, claims the decision was taken just among a handful of senior Taliban leaders.

"Akhunzada was appointed in the same way to how Mullah Mansoor was appointed, without consulting with anyone," Manan Niazi said.

"Mullah Yaqoob has been promoted as well but is powerless and is not knowledgeable enough to lead the Taliban and our movement."

Manan Niazi said his breakaway faction will continue to fight against the Taliban under Akhunzada and will not stand united with "the group that has forgotten Mullah Omar's purpose".

"God has taken our revenge and Mullah Mansoor got killed. He was a shame to the Taliban movement and was completely opposite to Mullah Omar."